: Well, in absolute terms, there have only been 21 perfect games in the history of baseball, and the history of baseball goes back to the late 19th century. So that's a lot of games. In fact, there have been about 200,000 games played in baseball history. But since two pitchers start in every game, there have been about 400,000 starts. This means there's about a one - or it happens every 20,000 starts. Let's put it that way. So, it really is quite rare. There are a couple more things that are more rare, like hitting four home runs in a game, but that never got called a perfect game for a hitter, and this got called a perfect game for a pitcher. 'Cause, of course, it is. You can't do any better than setting down every batter. So, yeah, it's quite remarkable.

: Well, yes. This is what I would say. If you asked me before the season who this year is going to pitch a perfect game - you tell me, I have a crystal ball, it'll happen, who will do it - Humber would not be in the first 100 pitchers that I'd mention. He's the fifth starter for the White Sox. He's a guy who was a high draft pick but was kind of seen as a washout for a while. However, if you ask me what team will this happen against, I would immediately say the Seattle Mariners, because the Seattle Mariners have the worst on-base percentage - or they did last year. This year, they have the worst on-base percentage in the American League. And of all the stats, like home runs and batting average, on-base percentage is really the enemy or the thing to look at when you talk about a perfect game. One guy gets on base and there is no more perfect game. The other thing is I'd further say it would be the Seattle Mariners in Seattle because their ballpark is cavernous, and a fly ball pitcher - and Philip Humber, 13 of his outs were on fly balls. Unless the ball leaves the park, it kind of goes to die in outfielders' gloves. So that's what happened. The other really weird thing is - you just heard on that call - the last strike of the game would have been a walk, it would have been a ball had the batter, Brendan Ryan, not had a check swing. And it looked to me the check swing was a little (unintelligible) - it might have been a ball but the umpire called him out and A.J. Pierzynski threw to first.

MARTIN: OK. Lots of factors, obviously, but getting back to the rarity of this whole thing. There was a 34-year stretch when no one pitched a perfect game. So, it feels like we've had a few of these though in the last few years, right?

: We certainly have. I mean, Dallas Braden, Roy Halladay in 2010, and Mark Buehrle pitched a perfect game for the White Sox in 2009. Lots of explanations about why this happened. Well, first of all, in the last few years you have to realize there are many more teams in baseball than there ever were. Up until 1960, there were only 16 teams. So, once you have 30 teams, you double your chances of a perfect game and you have a longer season. Errors are going down, on-base percentage is going down - all these things factor in. But I think luck has a lot to do with it. And I also think that, you know, the more games you play, that's pretty much the single-most important thing. Maybe they'll be seen as less special in the years to come. I don't know.

MARTIN: OK. So, briefly, Mike, there was another big pitching story this past week. Jamie Moyer, 49 years old - he won a game, and this is a big deal, right, just winning this for him?

: Yeah. As rare as a perfect game is, you know, only one other 49-year-old has ever won a game, and it was the guy whose record he broke as the oldest pitcher. So, Jamie Moyer was 49 and 150 days. A guy by the name of Jack Quinn...

MARTIN: We should say Moyer plays for the Colorado Rockies.

: He's a Colorado Rockie pitcher. He's played for a lot of teams. He's gotten better as he got older. Jack Quinn was 49 years old in 1932. And I did a little actuarial work, because this is what the statistician has to do. And I noted that in 1932 when Jack Quinn got his win, he was 49 years old. But life expectancy was only 61, so Jack Quinn was sort of at 80 percent of life expectancy, whereas Moyer is at 63 percent of the life expectancy for males today. I called the Baseball Hall of Fame. They said the guy who was the oldest before Quinn was Cy Young. He was 44 years old in 1911, representing something like 83 percent of the life expectancy, relatively a fantastic feat for Cy Young.